Mix pudding with 2 cups of milk. Let stand to thicken. After it has thicken fold in cool whip. Line a 9x13 cake pan with whole graham crackers. Pour half of pudding mixture over graham crackers. Place another layer of graham crackers on top of pudding mixture. Pour remaing pudding mixture on top of graham crackers and top with another layer of graham crackers. Warm chocolate icing in microwave so it is just warm enough to be able to pour. (Be sure not to over heat) Pour frosting over the third and final layer of graham crackers. Refrigerate for at least 2 hours. It's a hit at any family get together.